1. Field of the Invention
This invention resides in the field of materials handling equipment used in the construction industry or related industries where earth moving or materials loading is performed. In particular, this invention addresses buckets such as those used on tractors, rubber-tired loader backhoes, and track- or wheel-mounted excavators, and heavy machinery in general that is designed for lateral tilting in addition to vertical tilting.
2. Description of the Prior Art
The term “backhoe” generally refers to a boom with a normally vertical arm pivotally mounted to one end and a rectangular bucket pivotally mounted to the end of the arm, the boom itself being pivotally mounted at its other end to a power source. The combination of boom, arm and bucket is able to pivot within a single plane, forward or back, and in many cases the bucket can be pivoted laterally as well. The term “loader,” or particularly “front loader,” generally refers to a tractor that has a wide rectangular bucket mounted to its front end. The term “loader backhoe” generally refers to a tractor that has a loader with a wide rectangular bucket on the front and a backhoe on the rear, the backhoe being able to swing right or left over a range of no more than 200 degrees. The term “excavator” generally refers to a backhoe mounted singularly to a power source, the entire upper structure of the backhoe being able to rotate right or left over a range of 360 degrees. Each of these types of machinery are designed for scooping, lifting, moving, and depositing material such as sand, soil, gravel, and mud, and in some cases transporting materials to or from a worksite. Loading and unloading functions of a bucket are typically performed by a vertical tilting movement, i.e., tilting about an axis parallel to the width of the bucket. In certain applications, this vertical tilting is sufficient. In others, however, such as those involving an uneven terrain or areas with narrow access, tilting from side to side, or lateral tilting, is also needed. For these applications, lateral tilting buckets that are operated by hydraulic mechanisms are used. Descriptions of buckets for loaders, backhoes, and excavators are found in the following United States patents:                U.S. Pat. No. 5,964,301 to Glasgow, K. E., issued Oct. 12, 1999        U.S. Pat. No. 4,080,746 to Frazzini, T. G., issued Mar. 28, 1978        U.S. Pat. No. 4,999,022 to Veys, J. M., issued Mar. 12, 1991        U.S. Pat. No. 4,906,161 to Weyer, P. P., issued Mar. 6, 1990        U.S. Pat. No. 4,274,797 to Coon, D. B., issued Jun. 23, 1981        U.S. Pat. No. 4,042,131 to Buttke, F. P., issued Aug. 16, 1977        
Lateral tilting mechanisms complicate the construction of the bucket since they typically require hydraulic components that must be securely mounted and aligned, and they must be able to withstand strong impacts and forces and handle heavy loads without damage to the mechanism. Mechanisms that require this level of strength and durability while providing freedom of rotation in several different directions result in equipment that is expensive to manufacture and unwieldy in construction.